Non-minimal Derivative Coupling Scalar Field and Bulk Viscous Dark Energy

TL;DR

This paper introduces a viscous dark energy model with a non-minimal derivative coupling scalar field, fitting observational data and alleviating Hubble tension, while allowing phantom crossing and addressing age crisis issues.

Contribution

It proposes a novel scalar field model with bulk viscosity that explains accelerated expansion and fits multiple observational datasets, improving upon previous dark energy models.

Findings

Model fits observational data with $oxed{ ext{Ω}_ ext{DE}^0=0.696 ext{, } ext{γ}=0.1404$

Alleviates Hubble tension in cosmological measurements

Supports phantom crossing and addresses age crisis in cosmology

Abstract

Inspired by thermodynamical dissipative phenomena, we consider bulk viscosity for dark fluid in a spatially flat two-component Universe. Our viscous dark energy model represents Phantom crossing avoiding Big-Rip singularity. We propose a non-minimal derivative coupling scalar field with zero potential leading to accelerated expansion of Universe in the framework of bulk viscous dark energy model. In this approach, coupling constant ($\kappa$) is related to viscosity coefficient ($\gamma$) and energy density of dark energy at the present time ($\Omega_{\rm DE}^0$). This coupling is bounded as $\kappa\in [-1/9H_0^2(1-\Omega_{\rm DE}^0), 0]$ and for $\gamma=0$ leads to $\kappa=0$. To perform robust analysis, we implement recent observational data sets including Joint Light-curve Analysis (JLA) for SNIa, Gamma Ray Bursts (GRBs) for most luminous astrophysical objects at high redshifts, Baryon Acoustic Oscillations (BAO) from different surveys, Hubble parameter from HST project, {\it Planck} data for CMB power spectrum and CMB Lensing. Joint analysis of JLA$+$GRBs$+$BAO$+$HST shows that $\Omega_{\rm DE}^0=0.696\pm 0.010$, $\gamma=0.1404\pm0.0014$ and $H_0=68.1\pm1.3$ at $1\sigma$ confidence interval. {\it Planck} TT observation provides $\gamma=0.32^{+0.31}_{-0.26}$ at $68\%$ confidence limit for viscosity coefficient. Tension in Hubble parameter is alleviated in this model. Cosmographic distance ratio indicates that current observed data prefer to increase bulk viscosity. Finally, the competition between Phantom and Quintessence behavior of viscous dark energy model can accommodate cosmological old objects reported as a sign of age crisis in $\Lambda$CDM model.